there is a lot that goes into the equation.
Some types of beer benifit from aging and some do not. Some won't taste good when new, but after aging they taste great, so 6 bmonths is a bad limit to put on all beers. I would try to eliminate temp fluxs though. You can put you beer in a spare cooler if there is only a small amount, or make an insulated closet into a beer storage unit. The cooler the better for most types. Some light flavored beers may turn a little harsh after a long while in storage, but they are still better than commercial.
Are you slowing down on your consumption, or are you just trying to make a stockpile for the summer?

My consumption would never slow down! Heaven forbid that ever happen. Might as well put me out of my misery!
I'm new at this (4th batch) and I'm ready to bottle an Oatmeal Stout. I should've made this before winter since it taste so good during the cold months. But come the spring and summer I don't think I would really enjoy such a heavy beer. And I don't want to suck down 2 cases of stout due to the fact that I'm trying to keep my huge beer belly down! So I was thinking of storing some and drink it slowly during the summer and/or fall time.
My temps is just a guess since I never checked it during the summer times. But I would say its more stable then I put down. One other question: I've read different things about caps- boil before or don't boil?

Never, ever boil the caps.
You may damage the lining that is in it. They sell oxygen absorber caps, that are supposed to help in long storage of homebrew. If you are stockpiling future batches, this may be an option for you. Since it is just two cases, you may want to put it in a spare cooler to keep the temps low and stable. Beer is a living thing, especially homebrew, so if aged, it may taste different over time, but it isn't like it is going to make you sick if it is "past its born on date" I guess I have drank plenty of old beer. Anyway enjoy it. The stout you made, may taste even better this fall, after the hops subside a little and bottle condition.

When I first started brewing I made a cherry stout, at the time I wasnt that big on stouts, so I drank them slowly. I then stopped brewwing for a while, but would pull out a stout every once in a while. The last 2 I had werre about 3 years old when I drank them, man were they good. They aged perfectly. I would say for something like a stout if you just want to age them over the summer into next winter, they will only get better
Ed

The biggest factor in cellaring your beer is the percentage of alcohol. If it is 7% or greater than you would definitely benefit from aging your beer. The next biggest factor is the complexity of your brew. If you are adding a complex mixture of malts, hops, spice, fruits, chocolate, coffee, etc., etc., etc. then your beer may benefit from some aging. Cellar your beers differently than your wine though. You want to have your brew standing-up, not lying-down. You want as little light contact as possible, and you want to maintain a cool 55-68 degrees.
I currently have a few beers by Stone Brewing Company called "Vertical Epic" that are meant to be aged for a VERY long time. They started with the 02.02.02 released on February 2nd, 2002. Then this past Monday they released 03.03.03 , next year will be the 04.04.04 and they will continue this all the way up to 12.12.12 At which time you are supposed to open all of your beers that you have been hoarding away and have one helluva party.